1STRFTIME(3P) POSIX Programmer's Manual STRFTIME(3P)
2
3
4
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 strftime, strftime_l — convert date and time to a string
13
15 #include <time.h>
16
17 size_t strftime(char *restrict s, size_t maxsize,
18 const char *restrict format, const struct tm *restrict timeptr);
19 size_t strftime_l(char *restrict s, size_t maxsize,
20 const char *restrict format, const struct tm *restrict timeptr,
21 locale_t locale);
22
24 For strftime(): The functionality described on this reference page is
25 aligned with the ISO C standard. Any conflict between the requirements
26 described here and the ISO C standard is unintentional. This volume of
27 POSIX.1‐2017 defers to the ISO C standard.
28
29 The strftime() function shall place bytes into the array pointed to by
30 s as controlled by the string pointed to by format. The format is a
31 character string, beginning and ending in its initial shift state, if
32 any. The format string consists of zero or more conversion specifica‐
33 tions and ordinary characters.
34
35 Each conversion specification is introduced by the '%' character after
36 which the following appear in sequence:
37
38 * An optional flag:
39
40 0 The zero character ('0'), which specifies that the character
41 used as the padding character is '0',
42
43 + The <plus-sign> character ('+'), which specifies that the
44 character used as the padding character is '0', and that if
45 and only if the field being produced consumes more than four
46 bytes to represent a year (for %F, %G, or %Y) or more than
47 two bytes to represent the year divided by 100 (for %C) then
48 a leading <plus-sign> character shall be included if the year
49 being processed is greater than or equal to zero or a leading
50 <hyphen-minus> character ('-') shall be included if the year
51 is less than zero.
52
53 The default padding character is unspecified.
54
55 * An optional minimum field width. If the converted value, including
56 any leading '+' or '-' sign, has fewer bytes than the minimum field
57 width and the padding character is not the NUL character, the out‐
58 put shall be padded on the left (after any leading '+' or '-' sign)
59 with the padding character.
60
61 * An optional E or O modifier.
62
63 * A terminating conversion specifier character that indicates the
64 type of conversion to be applied.
65
66 The results are unspecified if more than one flag character is speci‐
67 fied, a flag character is specified without a minimum field width; a
68 minimum field width is specified without a flag character; a modifier
69 is specified with a flag or with a minimum field width; or if a minimum
70 field width is specified for any conversion specifier other than C, F,
71 G, or Y.
72
73 All ordinary characters (including the terminating NUL character) are
74 copied unchanged into the array. If copying takes place between objects
75 that overlap, the behavior is undefined. No more than maxsize bytes are
76 placed into the array. Each conversion specifier is replaced by appro‐
77 priate characters as described in the following list. The appropriate
78 characters are determined using the LC_TIME category of the current
79 locale and by the values of zero or more members of the broken-down
80 time structure pointed to by timeptr, as specified in brackets in the
81 description. If any of the specified values are outside the normal
82 range, the characters stored are unspecified.
83
84 The strftime_l() function shall be equivalent to the strftime() func‐
85 tion, except that the locale data used is from the locale represented
86 by locale.
87
88 Local timezone information is used as though strftime() called tzset().
89
90 The following conversion specifiers shall be supported:
91
92 a Replaced by the locale's abbreviated weekday name. [tm_wday]
93
94 A Replaced by the locale's full weekday name. [tm_wday]
95
96 b Replaced by the locale's abbreviated month name. [tm_mon]
97
98 B Replaced by the locale's full month name. [tm_mon]
99
100 c Replaced by the locale's appropriate date and time representa‐
101 tion. (See the Base Definitions volume of POSIX.1‐2017,
102 <time.h>.)
103
104 C Replaced by the year divided by 100 and truncated to an inte‐
105 ger, as a decimal number. [tm_year]
106
107 If a minimum field width is not specified, the number of char‐
108 acters placed into the array pointed to by s will be the number
109 of digits in the year divided by 100 or two, whichever is
110 greater. If a minimum field width is specified, the number of
111 characters placed into the array pointed to by s will be the
112 number of digits in the year divided by 100 or the minimum
113 field width, whichever is greater.
114
115 d Replaced by the day of the month as a decimal number [01,31].
116 [tm_mday]
117
118 D Equivalent to %m/%d/%y. [tm_mon, tm_mday, tm_year]
119
120 e Replaced by the day of the month as a decimal number [1,31]; a
121 single digit is preceded by a space. [tm_mday]
122
123 F Equivalent to %+4Y-%m-%d if no flag and no minimum field width
124 are specified. [tm_year, tm_mon, tm_mday]
125
126 If a minimum field width of x is specified, the year shall be
127 output as if by the Y specifier (described below) with whatever
128 flag was given and a minimum field width of x-6. If x is less
129 than 6, the behavior shall be as if x equalled 6.
130
131 If the minimum field width is specified to be 10, and the year
132 is four digits long, then the output string produced will match
133 the ISO 8601:2004 standard subclause 4.1.2.2 complete represen‐
134 tation, extended format date representation of a specific day.
135 If a + flag is specified, a minimum field width of x is speci‐
136 fied, and x-7 bytes are sufficient to hold the digits of the
137 year (not including any needed sign character), then the output
138 will match the ISO 8601:2004 standard subclause 4.1.2.4 com‐
139 plete representation, expanded format date representation of a
140 specific day.
141
142 g Replaced by the last 2 digits of the week-based year (see
143 below) as a decimal number [00,99]. [tm_year, tm_wday, tm_yday]
144
145 G Replaced by the week-based year (see below) as a decimal number
146 (for example, 1977). [tm_year, tm_wday, tm_yday]
147
148 If a minimum field width is specified, the number of characters
149 placed into the array pointed to by s will be the number of
150 digits and leading sign characters (if any) in the year, or the
151 minimum field width, whichever is greater.
152
153 h Equivalent to %b. [tm_mon]
154
155 H Replaced by the hour (24-hour clock) as a decimal number
156 [00,23]. [tm_hour]
157
158 I Replaced by the hour (12-hour clock) as a decimal number
159 [01,12]. [tm_hour]
160
161 j Replaced by the day of the year as a decimal number [001,366].
162 [tm_yday]
163
164 m Replaced by the month as a decimal number [01,12]. [tm_mon]
165
166 M Replaced by the minute as a decimal number [00,59]. [tm_min]
167
168 n Replaced by a <newline>.
169
170 p Replaced by the locale's equivalent of either a.m. or p.m.
171 [tm_hour]
172
173 r Replaced by the time in a.m. and p.m. notation; in the POSIX
174 locale this shall be equivalent to %I:%M:%S %p. [tm_hour,
175 tm_min, tm_sec]
176
177 R Replaced by the time in 24-hour notation (%H:%M). [tm_hour,
178 tm_min]
179
180 S Replaced by the second as a decimal number [00,60]. [tm_sec]
181
182 t Replaced by a <tab>.
183
184 T Replaced by the time (%H:%M:%S). [tm_hour, tm_min, tm_sec]
185
186 u Replaced by the weekday as a decimal number [1,7], with 1 rep‐
187 resenting Monday. [tm_wday]
188
189 U Replaced by the week number of the year as a decimal number
190 [00,53]. The first Sunday of January is the first day of week
191 1; days in the new year before this are in week 0. [tm_year,
192 tm_wday, tm_yday]
193
194 V Replaced by the week number of the year (Monday as the first
195 day of the week) as a decimal number [01,53]. If the week con‐
196 taining 1 January has four or more days in the new year, then
197 it is considered week 1. Otherwise, it is the last week of the
198 previous year, and the next week is week 1. Both January 4th
199 and the first Thursday of January are always in week 1.
200 [tm_year, tm_wday, tm_yday]
201
202 w Replaced by the weekday as a decimal number [0,6], with 0 rep‐
203 resenting Sunday. [tm_wday]
204
205 W Replaced by the week number of the year as a decimal number
206 [00,53]. The first Monday of January is the first day of week
207 1; days in the new year before this are in week 0. [tm_year,
208 tm_wday, tm_yday]
209
210 x Replaced by the locale's appropriate date representation. (See
211 the Base Definitions volume of POSIX.1‐2017, <time.h>.)
212
213 X Replaced by the locale's appropriate time representation. (See
214 the Base Definitions volume of POSIX.1‐2017, <time.h>.)
215
216 y Replaced by the last two digits of the year as a decimal number
217 [00,99]. [tm_year]
218
219 Y Replaced by the year as a decimal number (for example, 1997).
220 [tm_year]
221
222 If a minimum field width is specified, the number of characters
223 placed into the array pointed to by s will be the number of
224 digits and leading sign characters (if any) in the year, or the
225 minimum field width, whichever is greater.
226
227 z Replaced by the offset from UTC in the ISO 8601:2004 standard
228 format (+hhmm or -hhmm), or by no characters if no timezone is
229 determinable. For example, "-0430" means 4 hours 30 minutes
230 behind UTC (west of Greenwich). If tm_isdst is zero, the stan‐
231 dard time offset is used. If tm_isdst is greater than zero, the
232 daylight savings time offset is used. If tm_isdst is negative,
233 no characters are returned. [tm_isdst]
234
235 Z Replaced by the timezone name or abbreviation, or by no bytes
236 if no timezone information exists. [tm_isdst]
237
238 % Replaced by %.
239
240 If a conversion specification does not correspond to any of the above,
241 the behavior is undefined.
242
243 If a struct tm broken-down time structure is created by localtime() or
244 localtime_r(), or modified by mktime(), and the value of TZ is subse‐
245 quently modified, the results of the %Z and %z strftime() conversion
246 specifiers are undefined, when strftime() is called with such a broken-
247 down time structure.
248
249 If a struct tm broken-down time structure is created or modified by
250 gmtime() or gmtime_r(), it is unspecified whether the result of the %Z
251 and %z conversion specifiers shall refer to UTC or the current local
252 timezone, when strftime() is called with such a broken-down time struc‐
253 ture.
254
255 Modified Conversion Specifiers
256 Some conversion specifiers can be modified by the E or O modifier char‐
257 acters to indicate that an alternative format or specification should
258 be used rather than the one normally used by the unmodified conversion
259 specifier. If the alternative format or specification does not exist
260 for the current locale (see ERA in the Base Definitions volume of
261 POSIX.1‐2017, Section 7.3.5, LC_TIME), the behavior shall be as if the
262 unmodified conversion specification were used.
263
264 %Ec Replaced by the locale's alternative appropriate date and time
265 representation.
266
267 %EC Replaced by the name of the base year (period) in the locale's
268 alternative representation.
269
270 %Ex Replaced by the locale's alternative date representation.
271
272 %EX Replaced by the locale's alternative time representation.
273
274 %Ey Replaced by the offset from %EC (year only) in the locale's
275 alternative representation.
276
277 %EY Replaced by the full alternative year representation.
278
279 %Od Replaced by the day of the month, using the locale's alterna‐
280 tive numeric symbols, filled as needed with leading zeros if
281 there is any alternative symbol for zero; otherwise, with lead‐
282 ing <space> characters.
283
284 %Oe Replaced by the day of the month, using the locale's alterna‐
285 tive numeric symbols, filled as needed with leading <space>
286 characters.
287
288 %OH Replaced by the hour (24-hour clock) using the locale's alter‐
289 native numeric symbols.
290
291 %OI Replaced by the hour (12-hour clock) using the locale's alter‐
292 native numeric symbols.
293
294 %Om Replaced by the month using the locale's alternative numeric
295 symbols.
296
297 %OM Replaced by the minutes using the locale's alternative numeric
298 symbols.
299
300 %OS Replaced by the seconds using the locale's alternative numeric
301 symbols.
302
303 %Ou Replaced by the weekday as a number in the locale's alternative
304 representation (Monday=1).
305
306 %OU Replaced by the week number of the year (Sunday as the first
307 day of the week, rules corresponding to %U) using the locale's
308 alternative numeric symbols.
309
310 %OV Replaced by the week number of the year (Monday as the first
311 day of the week, rules corresponding to %V) using the locale's
312 alternative numeric symbols.
313
314 %Ow Replaced by the number of the weekday (Sunday=0) using the
315 locale's alternative numeric symbols.
316
317 %OW Replaced by the week number of the year (Monday as the first
318 day of the week) using the locale's alternative numeric sym‐
319 bols.
320
321 %Oy Replaced by the year (offset from %C) using the locale's alter‐
322 native numeric symbols.
323
324 %g, %G, and %V give values according to the ISO 8601:2004 standard
325 week-based year. In this system, weeks begin on a Monday and week 1 of
326 the year is the week that includes January 4th, which is also the week
327 that includes the first Thursday of the year, and is also the first
328 week that contains at least four days in the year. If the first Monday
329 of January is the 2nd, 3rd, or 4th, the preceding days are part of the
330 last week of the preceding year; thus, for Saturday 2nd January 1999,
331 %G is replaced by 1998 and %V is replaced by 53. If December 29th,
332 30th, or 31st is a Monday, it and any following days are part of week 1
333 of the following year. Thus, for Tuesday 30th December 1997, %G is
334 replaced by 1998 and %V is replaced by 01.
335
336 If a conversion specifier is not one of the above, the behavior is
337 undefined.
338
339 The behavior is undefined if the locale argument to strftime_l() is the
340 special locale object LC_GLOBAL_LOCALE or is not a valid locale object
341 handle.
342
344 If the total number of resulting bytes including the terminating null
345 byte is not more than maxsize, these functions shall return the number
346 of bytes placed into the array pointed to by s, not including the ter‐
347 minating NUL character. Otherwise, 0 shall be returned and the contents
348 of the array are unspecified.
349
351 No errors are defined.
352
353 The following sections are informative.
354
356 Getting a Localized Date String
357 The following example first sets the locale to the user's default. The
358 locale information will be used in the nl_langinfo() and strftime()
359 functions. The nl_langinfo() function returns the localized date string
360 which specifies how the date is laid out. The strftime() function takes
361 this information and, using the tm structure for values, places the
362 date and time information into datestring.
363
364
365 #include <time.h>
366 #include <locale.h>
367 #include <langinfo.h>
368 ...
369 struct tm *tm;
370 char datestring[256];
371 ...
372 setlocale (LC_ALL, "");
373 ...
374 strftime (datestring, sizeof(datestring), nl_langinfo (D_T_FMT), tm);
375 ...
376
378 The range of values for %S is [00,60] rather than [00,59] to allow for
379 the occasional leap second.
380
381 Some of the conversion specifications are duplicates of others. They
382 are included for compatibility with nl_cxtime() and nl_ascxtime(),
383 which were published in Issue 2.
384
385 The %C, %F, %G, and %Y format specifiers in strftime() always print
386 full values, but the strptime() %C, %F, and %Y format specifiers only
387 scan two digits (assumed to be the first two digits of a four-digit
388 year) for %C and four digits (assumed to be the entire (four-digit)
389 year) for %F and %Y. This mimics the behavior of printf() and scanf();
390 that is:
391
392
393 printf("%2d", x = 1000);
394
395 prints "1000", but:
396
397
398 scanf(%2d", &x);
399
400 when given "1000" as input will only store 10 in x). Applications
401 using extended ranges of years must be sure that the number of digits
402 specified for scanning years with strptime() matches the number of dig‐
403 its that will actually be present in the input stream. Historic imple‐
404 mentations of the %Y conversion specification (with no flags and no
405 minimum field width) produced different output formats. Some always
406 produced at least four digits (with 0 fill for years from 0 through
407 999) while others only produced the number of digits present in the
408 year (with no fill and no padding). These two forms can be produced
409 with the '0' flag and a minimum field width options using the conver‐
410 sions specifications %04Y and %01Y, respectively.
411
412 In the past, the C and POSIX standards specified that %F produced an
413 ISO 8601:2004 standard date format, but didn't specify which one. For
414 years in the range [0001,9999], POSIX.1‐2008 requires that the output
415 produced match the ISO 8601:2004 standard complete representation
416 extended format (YYYY-MM-DD) and for years outside of this range pro‐
417 duce output that matches the ISO 8601:2004 standard expanded represen‐
418 tation extended format (<+/-><Underline>Y</Underline>YYYY-MM-DD). To
419 fully meet ISO 8601:2004 standard requirements, the producer and con‐
420 sumer must agree on a date format that has a specific number of bytes
421 reserved to hold the characters used to represent the years that is
422 sufficiently large to hold all values that will be shared. For example,
423 the %+13F conversion specification will produce output matching the
424 format "<+/->YYYYYY-MM-DD" (a leading '+' or '-' sign; a six-digit,
425 0-filled year; a '-'; a two-digit, leading 0-filled month; another '-';
426 and the two-digit, leading 0-filled day within the month).
427
428 Note that if the year being printed is greater than 9999, the resulting
429 string from the unadorned %F conversion specifications will not conform
430 to the ISO 8601:2004 standard extended format, complete representation
431 for a date and will instead be an extended format, expanded representa‐
432 tion (presumably without the required agreement between the date's pro‐
433 ducer and consumer).
434
435 In the C or POSIX locale, the E and O modifiers are ignored and the
436 replacement strings for the following specifiers are:
437
438 %a The first three characters of %A.
439
440 %A One of Sunday, Monday, ..., Saturday.
441
442 %b The first three characters of %B.
443
444 %B One of January, February, ..., December.
445
446 %c Equivalent to %a %b %e %T %Y.
447
448 %p One of AM or PM.
449
450 %r Equivalent to %I:%M:%S %p.
451
452 %x Equivalent to %m/%d/%y.
453
454 %X Equivalent to %T.
455
456 %Z Implementation-defined.
457
459 The %Y conversion specification to strftime() was frequently assumed to
460 be a four-digit year, but the ISO C standard does not specify that %Y
461 is restricted to any subset of allowed values from the tm_year field.
462 Similarly, the %C conversion specification was assumed to be a two-
463 digit field and the first part of the output from the %F conversion
464 specification was assumed to be a four-digit field. With tm_year being
465 a signed 32 or more-bit int and with many current implementations sup‐
466 porting 64-bit time_t types in one or more programming environments,
467 these assumptions are clearly wrong.
468
469 POSIX.1‐2008 now allows the format specifications %0xC, %0xF, %0xG, and
470 %0xY (where 'x' is a string of decimal digits used to specify printing
471 and scanning of a string of x decimal digits) with leading zero fill
472 characters. Allowing applications to set the field width enables them
473 to agree on the number of digits to be printed and scanned in the
474 ISO 8601:2004 standard expanded representation of a year (for %F, %G,
475 and %Y) or all but the last two digits of the year (for %C). This is
476 based on a feature in some versions of GNU libc's strftime(). The GNU
477 version allows specifying space, zero, or no-fill characters in strf‐
478 time() format strings, but does not allow any flags to be specified in
479 strptime() format strings. These implementations also allow these flags
480 to be specified for any numeric field. POSIX.1‐2008 only requires the
481 zero fill flag ('0') and only requires that it be recognized when pro‐
482 cessing %C, %F, %G, and %Y specifications when a minimum field width is
483 also specified. The '0' flag is the only flag needed to produce and
484 scan the ISO 8601:2004 standard year fields using the extended format
485 forms. POSIX.1‐2008 also allows applications to specify the same flag
486 and field width specifiers to be used in both strftime() and strptime()
487 format strings for symmetry. Systems may provide other flag characters
488 and may accept flags in conjunction with conversion specifiers other
489 than %C, %F, %G, and %Y; but portable applications cannot depend on
490 such extensions.
491
492 POSIX.1‐2008 now also allows the format specifications %+xC, %+xF,
493 %+xG, and %+xY (where 'x' is a string of decimal digits used to specify
494 printing and scanning of a string of 'x' decimal digits) with leading
495 zero fill characters and a leading '+' sign character if the year being
496 converted is more than four digits or a minimum field width is speci‐
497 fied that allows room for more than four digits for the year. This
498 allows date providers and consumers to agree on a specific number of
499 digits to represent a year as required by the ISO 8601:2004 standard
500 expanded representation formats. The expanded representation formats
501 all require the year to begin with a leading '+' or '-' sign. (All of
502 these specifiers can also provide a leading '-' sign for negative
503 years. Since negative years and the year 0 don't fit well with the Gre‐
504 gorian or Julian calendars, the normal ranges of dates start with year
505 1. The ISO C standard allows tm_year to assume values corresponding to
506 years before year 1, but the use of such years provided unspecified
507 results.)
508
509 Some earlier version of this standard specified that applications want‐
510 ing to use strptime() to scan dates and times printed by strftime()
511 should provide non-digit characters between fields to separate years
512 from months and days. It also supported %F to print and scan the
513 ISO 8601:2004 standard extended format, complete representation date
514 for years 1 through 9999 (i.e., YYYY-MM-DD). However, many applications
515 were written to print (using strftime()) and scan (using strptime())
516 dates written using the basic format complete representation (four-
517 digit years) and truncated representation (two-digit years) specified
518 by the ISO 8601:2004 standard representation of dates and times which
519 do not have any separation characters between fields. The ISO 8601:2004
520 standard also specifies basic format expanded representation where the
521 creator and consumer of these fields agree beforehand to represent
522 years as leading zero-filled strings of an agreed length of more than
523 four digits to represent a year (again with no separation characters
524 when year, month, and day are all displayed). Applications producing
525 and consuming expanded representations are encouraged to use the '+'
526 flag and an appropriate maximum field width to scan the year including
527 the leading sign. Note that even without the '+' flag, years less than
528 zero may be represented with a leading <hyphen-minus> for %F, %G, and
529 %Y conversion specifications. Using negative years results in unspeci‐
530 fied behavior.
531
532 If a format specification %+xF with the field width x greater than 11
533 is specified and the width is large enough to display the full year,
534 the output string produced will match the ISO 8601:2004 standard sub‐
535 clause 4.1.2.4 expanded representation, extended format date represen‐
536 tation for a specific day. (For years in the range [1,99999], %+12F is
537 sufficient for an agreed five-digit year with a leading sign using the
538 ISO 8601:2004 standard expanded representation, extended format for a
539 specific day "<+/->YYYYY-MM-DD".) Note also that years less than 0 may
540 produce a leading <hyphen-minus> character ('-') when using %Y or %C
541 whether or not the '0' or '+' flags are used.
542
543 The difference between the '0' flag and the '+' flag is whether the
544 leading '+' character will be provided for years >9999 as required for
545 the ISO 8601:2004 standard extended representation format containing a
546 year. For example:
547
548 ┌───────┬──────────────────────────┬─────────────┬────────────┐
549 │ │ │ strftime() │ strptime() │
550 │ Year │ Conversion Specification │ Output │ Scan Back │
551 ├───────┼──────────────────────────┼─────────────┼────────────┤
552 │1970 │ %Y │ 1970 │ 1970 │
553 ├───────┼──────────────────────────┼─────────────┼────────────┤
554 │1970 │ %+4Y │ 1970 │ 1970 │
555 ├───────┼──────────────────────────┼─────────────┼────────────┤
556 │27 │ %Y │ 27 or 0027 │ 27 │
557 ├───────┼──────────────────────────┼─────────────┼────────────┤
558 │270 │ %Y │ 270 or 0270 │ 270 │
559 ├───────┼──────────────────────────┼─────────────┼────────────┤
560 │270 │ %+4Y │ 0270 │ 270 │
561 ├───────┼──────────────────────────┼─────────────┼────────────┤
562 │17 │ %C%y │ 0017 │ 17 │
563 ├───────┼──────────────────────────┼─────────────┼────────────┤
564 │270 │ %C%y │ 0270 │ 270 │
565 ├───────┼──────────────────────────┼─────────────┼────────────┤
566 │12345 │ %Y │ 12345 │ 1234* │
567 ├───────┼──────────────────────────┼─────────────┼────────────┤
568 │12345 │ %+4Y │ +12345 │ 123* │
569 ├───────┼──────────────────────────┼─────────────┼────────────┤
570 │12345 │ %05Y │ 12345 │ 12345 │
571 ├───────┼──────────────────────────┼─────────────┼────────────┤
572 │270 │ %+5Y or %+3C%y │ +0270 │ 270 │
573 ├───────┼──────────────────────────┼─────────────┼────────────┤
574 │12345 │ %+5Y or %+3C%y │ +12345 │ 1234* │
575 ├───────┼──────────────────────────┼─────────────┼────────────┤
576 │12345 │ %06Y or %04C%y │ 012345 │ 12345 │
577 ├───────┼──────────────────────────┼─────────────┼────────────┤
578 │12345 │ %+6Y or %+4C%y │ +12345 │ 12345 │
579 ├───────┼──────────────────────────┼─────────────┼────────────┤
580 │123456 │ %08Y or %06C%y │ 00123456 │ 123456 │
581 ├───────┼──────────────────────────┼─────────────┼────────────┤
582 │123456 │ %+8Y or %+6C%y │ +0123456 │ 123456 │
583 └───────┴──────────────────────────┴─────────────┴────────────┘
584 In the cases above marked with a * in the strptime() scan back field,
585 the implied or specified number of characters scanned by strptime() was
586 less than the number of characters output by strftime() using the same
587 format; so the remaining digits of the year were dropped when the out‐
588 put date produced by strftime() was scanned back in by strptime().
589
591 None.
592
594 asctime(), clock(), ctime(), difftime(), getdate(), gmtime(), local‐
595 time(), mktime(), strptime(), time(), tzset(), uselocale(), utime()
596
597 The Base Definitions volume of POSIX.1‐2017, Section 7.3.5, LC_TIME,
598 <time.h>
599
601 Portions of this text are reprinted and reproduced in electronic form
602 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
603 table Operating System Interface (POSIX), The Open Group Base Specifi‐
604 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
605 Electrical and Electronics Engineers, Inc and The Open Group. In the
606 event of any discrepancy between this version and the original IEEE and
607 The Open Group Standard, the original IEEE and The Open Group Standard
608 is the referee document. The original Standard can be obtained online
609 at http://www.opengroup.org/unix/online.html .
610
611 Any typographical or formatting errors that appear in this page are
612 most likely to have been introduced during the conversion of the source
613 files to man page format. To report such errors, see https://www.ker‐
614 nel.org/doc/man-pages/reporting_bugs.html .
615
616
617
618IEEE/The Open Group 2017 STRFTIME(3P)